Rapid-Sequence Intubation (RSI)

Definition

Indications

• Airway protection in the unconscious or obtunded patient
• Respiratory failure (hypoxic or hypercapnic)
• Anticipated deterioration of airway (angioedema, burns, trauma)
• Status epilepticus requiring airway control
• Shock states where airway is compromised

Relative Contraindications

• Anticipated difficult airway (anatomic abnormalities that muscle relaxation will not help)
• Clinical scenarios where relaxation will not improve laryngeal exposure (massive edema, immobile jaw, oral tumors/obstruction)
• Always have a rescue airway plan and equipment ready before initiating RSI

The RSI Steps (Table 29A-6, Tintinalli)

1. Discuss airway management strategy with the team
2. Set up IV access, cardiac monitor, pulse oximetry, capnography/capnometry
3. Plan procedure - assess physiologic status and airway difficulty
4. Prepare equipment, suction, and potential rescue devices
5. Preoxygenate
6. Consider pretreatment agents
7. Give sedative agent immediately followed by neuromuscular blocking agent
8. Intubate the trachea
9. Confirm tube placement (capnography/colorimetric CO₂ detector)
10. Secure the tube
11. Adjust mechanical ventilation and provide post-intubation sedation

Preoxygenation

• Critical step to extend safe apnea time
• Goal: denitrogenate the lungs to create an oxygen reservoir (target SpO₂ ≥ 95%, ideally 100%)
• Methods: high-flow O₂ via non-rebreather mask (100% O₂ for 3 minutes of tidal breathing, or 8 vital-capacity breaths), or apneic oxygenation (high-flow nasal cannula at 15 L/min maintained throughout laryngoscopy)
• Avoid aggressive BVM ventilation prior to intubation to reduce aspiration risk

Pretreatment Agents (Table 29A-7, Tintinalli)

Induction (Sedative) Agents (Table 29A-8, Tintinalli)

Paralytic (Neuromuscular Blocking) Agents (Table 29A-9, Tintinalli)

Succinylcholine (Depolarizing Agent)

• Dose: 1.5 mg/kg IV (children <10 kg: 1.5-2 mg/kg; >10 kg: 1.0-1.5 mg/kg)
• Onset: ~45 seconds; Duration: 8-10 minutes (ultra-short acting)
• Mechanism: Depolarizing agent - high affinity for cholinergic receptors at motor end plate, resistant to acetylcholinesterase
• Advantages: Ultra-rapid onset; short duration (allows reassessment if intubation fails)
• Absolute contraindications: Hyperkalemia (risk of fatal cardiac arrest), denervation injury, crush injury >72 hrs, burns >72 hrs, prolonged immobility, rhabdomyolysis, undiagnosed neuromuscular disease (especially in children), personal/family history of malignant hyperthermia, open globe injury
• Other adverse effects: Fasciculations, increased intraocular/intragastric pressure, bradycardia (especially in children), increased ICP

Rocuronium (Non-Depolarizing Agent)

• Dose: 1-1.2 mg/kg IV (RSI dose)
• Onset: 45-60 seconds at RSI doses; Duration: 30-60 minutes
• Mechanism: Competes with acetylcholine at nicotinic receptors
• Advantages: No contraindication in hyperkalemia; preferred in children due to risk of undiagnosed neuromuscular disease with succinylcholine; preferred if succinylcholine contraindicated
• Reversal: Can be reversed with sugammadex (16 mg/kg for immediate reversal)
• In children: rocuronium has largely replaced succinylcholine as the paralytic of choice in pediatric emergency medicine

Special Clinical Scenarios

Traumatic Brain Injury (TBI)

• Goal: Prevent secondary brain injury
• Use fentanyl pretreatment to blunt ICP spike from laryngoscopy
• Ketamine is acceptable (does not elevate ICP in sedated/ventilated patients); may be cerebroprotective
• Avoid hypotension (worsens cerebral perfusion) - etomidate or ketamine preferred over propofol
• Avoid hypoxia and hypercarbia

Hypotensive/Shock Patient

• Ketamine is the agent of choice (maintains hemodynamics via catecholamine release)
• Etomidate is reasonable (minimal hemodynamic depression)
• Avoid propofol (causes significant hypotension)
• Use "Shock Dose" - reduce induction agent dose by 50% if profoundly hypotensive

Severe Asthma / Bronchospasm

• Ketamine is preferred (direct bronchodilator, smooth muscle relaxation)
• Lidocaine pretreatment may help prevent laryngospasm/bronchospasm
• Patients should be intubated sitting upright when possible

Elevated ICP

• Fentanyl pretreatment (3 mcg/kg IV) 3 min before RSI
• Etomidate or ketamine as induction agent
• Avoid hypotension post-intubation

Pediatric RSI

• RSI remains the preferred method in children in the ED
• Associated with highest success and lowest complication rates
• Atropine does NOT prevent succinylcholine-associated bradycardia in children and should NOT be given prophylactically
• Bradycardia in children is typically a sign of hypoxia - correct hypoxia first
• Rocuronium preferred over succinylcholine in children due to risk of hyperkalemic cardiac arrest in undiagnosed neuromuscular disease
• No evidence supports pretreatment agents in children

Airway Confirmation

• Waveform capnography (gold standard) - continuous end-tidal CO₂ monitoring
• Colorimetric end-tidal CO₂ detector (use adult device for children >15 kg)
• Bilateral breath sounds on auscultation
• Absence of epigastric sounds
• Chest X-ray (confirmatory, not primary)
• Direct visualization of ETT passing through vocal cords

Post-Intubation Management

• Secure the ETT immediately
• Adjust mechanical ventilation settings
• Provide post-intubation sedation and analgesia (mandatory, especially with longer-acting paralytics like rocuronium)
• Monitor for and manage complications (Table 29A-5, Tintinalli):

Failed Airway / Rescue

• Have rescue airway devices ready (supraglottic airway: LMA, King tube)
• Surgical airway (cricothyrotomy) if "can't intubate, can't oxygenate"
• Sugammadex (16 mg/kg) can rapidly reverse rocuronium if intubation fails and spontaneous breathing must be restored
• Obesity, anatomic abnormalities, and difficult laryngoscopy are key risk factors - video laryngoscopy is the preferred primary device in many emergency departments

Prehospital RSI

• Critical care transport and ALS services perform RSI
• Raises the level of training, judgment, and psychomotor skills required
• Requires medical director oversight and ongoing quality assurance
• Smaller services with more intubation experience per provider (e.g., air medical) are better positioned to maintain RSI skills
• Carries risk of failed airway in setting of limited resources